If the sum of the interior angles of a regular polygon be 1080 °, the number of sides of the polygon is 

G is the centroid of ΔABC. The medians AD and BE intersect at right angles. If the lengths of AD and BE are 9 cm and 12 cm respectively; then the length of AB (in cm) is?

In a regular polygon, the exterior and interior angles are in the ration 1:4.The number of sides of the polygon is

Equation of the straight line parallel to x-axis and also 3 units below x-axis is: 

In triangle PQR, points A, B and C are taken on PQ, PR and QR respectively such that QC = AC and CR = CB. If ∠QPR = 40°, then ∠ACB is equal to: 

The measure of the angles of a triangle are in the ratio of 2 : 7: 11. Measure of angles are:

The radius of the circumcircle of a right-angled triangle is 15 cm and the radius of its in circle is 6 cm. Find the sides of the triangle. 

If each interior angle is doubled of each exterior angle of a regular polygon with n sides, then the value of n is